# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
1201694 | adiyer | Permutation (APIO22_perm) | C++20 | 0 ms | 0 KiB |
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
void add(vector < int > &v, int pos, int x){
vector < int > nw;
for(ll i = 0; i < pos; i++) nw.push_back(v[i]);
nw.push_back(x);
for(ll i = pos; i < v.size(); i++) nw.push_back(v[i]);
v = nw;
}
vector < ll > calc(vector < int > &v) {
vector < ll > dp(v.size() + 1, 0);
dp[0] = 1;
for(int x : v)
for(int i = 0; i <= x; i++)
dp[x + 1] += dp[i];
return dp;
}
vector < int > construct_permutation(ll k){
int x = 0;
vector < int > ans;
for(ll bit = 59; bit >= 0; bit--){
if(k >= (1ll << bit)){
for(int i = 0; i < bit; i++) ans.push_back(x++);
break;
}
}
while(1){
ll sum = 0, pos = 1;
vector < ll > dp = calc(ans);
for(ll val : dp) sum += val;
if(sum == k) break;
for(ll i = 0; i < dp.size(); i++)
if(sum + dp[i] <= k && dp[i] > dp[pos])
pos = i;
add(ans, pos - 1, x++);
// for(ll x : ans) cout << x << '\n';
}
return ans;
}
static long long MX = 1e18;
static bool check_permutation(vector<int> v)
{
sort(v.begin(),v.end());
for(int i=0;i<v.size();i++)
if(v[i]!=i) return 0;
return 1;
}
long long count_increasing(const vector<int>& v) {
vector<long long> dp(v.size() + 1, 0);
dp[0] = 1;
for (int x : v)
{
for (int i = 0; i <= x; i++)
{
dp[x+1] += dp[i];
dp[x+1] = min(dp[x+1],MX+1);
}
}
long long result = 0;
for (int i = 0; i <= (int)v.size(); i++){
result += dp[i];
result = min(result,MX+1);
}
return result;
}
int main() {
int t;
assert(1 == scanf("%d", &t));
while(t--)
{
long long k;
assert(1 == scanf("%lld",&k));
vector<int> ret=construct_permutation(k);
if(!check_permutation(ret))
{
printf("WA: Returned array is not a permutation\n");
exit(0);
}
long long inc=count_increasing(ret);
if(inc!=k)
{
if(inc==MX+1)
printf("WA: Expected %lld increasing subsequences, found more than %lld\n",k, MX);
else
printf("WA: Expected %lld increasing subsequences, found %lld\n",k,inc);
exit(0);
}
printf("%d\n",(int)ret.size());
for(int i=0;i<ret.size();i++)
{
printf("%d",ret[i]);
if(i+1==ret.size())
printf("\n");
else
printf(" ");
}
}
return 0;
}